package com.mall.concurrency.example.aqs;

import lombok.extern.slf4j.Slf4j;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;

/**
 * @Author:zwy
 * @Despriction:
 * @Date:Create in 10:34 2018/5/31
 * @Modify By:
 */
@Slf4j
public class SemaphoreExample {
    private static int threadCount = 20;
    public static void main(String[] args) throws Exception{
        ExecutorService exec = Executors.newCachedThreadPool();
        final Semaphore semaphore = new Semaphore(3);
        for(int i =0 ;i<threadCount;i++){
            final int threadNum = i;
            exec.execute(()->{
                try {
                    semaphore.acquire();//获取一个许可
                    test(threadNum);
                    semaphore.release();//释放一个许可
                } catch (Exception e) {
                    e.printStackTrace();
                }
            });
        }
        log.info("finish");
        exec.shutdown();


    }
    private static void test(int threadNum) throws Exception {

        log.info("{}",threadNum);
        Thread.sleep(1000);
    }

}
